1. Field of the Invention
The present invention relates to a motor of a washing machine, and more particularly, to a structure for cooling a motor of a washing machine.
2. Discussion of the Related Art
FIG. 1 is a cross-sectional view illustrating a related art washing machine.
As shown in FIG. 1, the related art washing machine is provided with a cabinet 100, an outer tub 110 and an inner tub 120. At this time, the outer tub 110 is supported with a damper, and the cylindrical inner tub 120 is rotatably provided inside the outer tub 110 to receive laundry therein. In the related art washing machine, a rotation power is generated by a motor, and then transmitted to the inner tub 120, whereby the inner tub 120 is rotated, thereby washing the laundry inside the inner tub 120.
The motor is provided so as to directly transmit the power generated by a rotor 130a and a stator 130b to a shaft 140 of the inner tub 120. That is, the motor is provided with the stator 130b receiving an electric current and generating a rotary magnetic field, and the rotor 130a generating the rotation power with the rotary magnetic field. According as the rotor 130a and a spin shaft press-fitted to the rotor 130a are rotated, the rotation power is directly transmitted to the shaft of the inner tub 120.
An operation of the related art washing machine will be described as follows.
When the motor is driven in regular/reverse directions, the rotation power of the motor is applied to the inner tub 120. As the inner tub 120 receiving the rotation power is rotated in regular/reverse directions, the laundry is washed according to impact action of washing water circulation and resolution action of detergent.
On driving the motor in regular/reverse directions, the heat is generated as the current is applied to a wire of the stator 130b. Then, the heat is transmitted to the stator 130b, so that the heat is dispersed in the circumference of the stator 130b. That is, the stator 130b serves as a guide of the wire. Simultaneously, the stator 130b disperses the heat generated in the wire so as to cool the motor. However, as mentioned above, in case of that the heat generated in the wire is dispersed spontaneously, cooling efficiency is lowered.
Meanwhile, a structure for cooling the motor of the washing machine according to the related art is provided with a rotor housing. Hereinafter, the structure for cooling the motor of the washing machine according to the related art will be described in detail.
FIG. 2 is a plan view illustrating a rotor housing 150 according to the related art, and FIG. 3 is a cross-sectional view taken along line B-B′ of FIG. 2.
The rotor housing 150 is provided in the circumference of the stator 130b. Also, as shown in FIG. 2, the rotor housing 150 is provided with a plurality of holes 210 and blades 220 at fixed intervals on a lower inner surface thereof. That is, referring to FIG. 3, the blade 220 is provided in the right side of the hole 210 to a central point of the rotor housing 150, whereby the blade 220 is provided at the same direction as a rotation of a dehydration process.
Thus, if the motor is rotated, the outside cold air flows into the inside of the rotor housing 150 by the blades 220, thereby cooling the inside of the motor assembly, the rotor 130a and the stator 130b. That is, the hot air inside the rotor housing 150 is moved upwardly, and then exhausted through a space between the rotor housing 150 and the outer tub.
However, the structure for cooling the motor of the washing machine according to the related art has the following disadvantages.
First, the blade 220 is provided in the side of the hole 210 to the central point of the rotor housing 150 at the same direction as the rotation of the dehydration process. When the motor is continuously rotated in the regular direction on the dehydration process, the outside air flows into the inside of the rotor housing 150 through the hole 210 in a small amount, thereby lowering the cooling efficiency.
Also, the blade 220 is provided in the side of the hole 210 for being upward to the lower surface of the rotor housing 150, whereby the outside cold air flows into the inside of the rotor housing 150 so as to cool the inside of the motor. At this time, the hot air inside the motor has bad effects on components adjoining to the upper part of the rotor 130a until the hot air is exhausted through the space between the outer tub and the rotor housing 150.